diff --git a/cmd_root.go b/cmd_root.go
index e9c803e..ac502fd 100644
--- a/cmd_root.go
+++ b/cmd_root.go
@@ -1,8 +1,6 @@
 package atom
 
 import (
-	"fmt"
-
 	"git.ipao.vip/rogeecn/atom/config"
 	"git.ipao.vip/rogeecn/atom/container"
 	"github.com/pkg/errors"
@@ -10,8 +8,6 @@ import (
 	"go.uber.org/dig"
 )
 
-var cfgFile string
-
 var (
 	GroupInitialName           = "initials"
 	GroupRoutesName            = "routes"
@@ -26,7 +22,7 @@ var (
 	GroupQueue      = dig.Group(GroupQueueName)
 )
 
-func Serve(providers container.Providers, opts ...Option) error {
+func Serve(opts ...Option) error {
 	rootCmd := &cobra.Command{Use: "app"}
 	for _, opt := range opts {
 		opt(rootCmd)
@@ -40,21 +36,15 @@ func Serve(providers container.Providers, opts ...Option) error {
 		return err
 	})
 
-	defaultCfgFile := fmt.Sprintf(".%s.toml", rootCmd.Use)
-	rootCmd.PersistentFlags().StringVarP(&cfgFile, "config", "c", "", "config file path, lookup in dir: $HOME, $PWD, /etc, /usr/local/etc, filename: "+defaultCfgFile)
-
-	rootCmd.PersistentPreRunE = func(cmd *cobra.Command, args []string) error {
-		return LoadProviders(cfgFile, rootCmd.Use, providers)
-	}
+	rootCmd.PersistentFlags().StringP("config", "c", "config.toml", "config file")
 
 	return rootCmd.Execute()
 }
 
-func LoadProviders(cfgFile, appName string, providers container.Providers) error {
-	// parse config files
-	configure, err := config.Load(cfgFile, appName)
+func LoadProviders(configFile string, providers container.Providers) error {
+	configure, err := config.Load(configFile)
 	if err != nil {
-		return errors.Wrapf(err, "load config file: %s", cfgFile)
+		return errors.Wrapf(err, "load config file: %s", configFile)
 	}
 
 	if err := providers.Provide(configure); err != nil {
@@ -70,6 +60,24 @@ var (
 	AppVersion string
 )
 
+func Providers(providers container.Providers) Option {
+	return func(cmd *cobra.Command) {
+		cmd.PreRunE = func(cmd *cobra.Command, args []string) error {
+			return LoadProviders(cmd.Flag("config").Value.String(), providers)
+		}
+	}
+}
+
+func Command(opt ...Option) Option {
+	return func(parentCmd *cobra.Command) {
+		cmd := &cobra.Command{}
+		for _, o := range opt {
+			o(cmd)
+		}
+		parentCmd.AddCommand(cmd)
+	}
+}
+
 func Version(ver string) Option {
 	return func(cmd *cobra.Command) {
 		cmd.Version = ver
diff --git a/config/config.go b/config/config.go
index f4c432c..ca7c190 100644
--- a/config/config.go
+++ b/config/config.go
@@ -2,7 +2,6 @@ package config
 
 import (
 	"log"
-	"os"
 	"path/filepath"
 
 	"github.com/pkg/errors"
@@ -10,38 +9,23 @@ import (
 	"github.com/spf13/viper"
 )
 
-func Load(file, app string) (*viper.Viper, error) {
+func Load(file string) (*viper.Viper, error) {
 	v := viper.NewWithOptions(viper.KeyDelimiter("_"))
 	v.AutomaticEnv()
 
-	if file == "" {
+	ext := filepath.Ext(file)
+	if ext == "" {
 		v.SetConfigType("toml")
-		v.SetConfigName(app + ".toml")
-
-		paths := []string{"."}
-		// execute path
-		execPath, err := os.Executable()
-		if err == nil {
-			paths = append(paths, filepath.Dir(execPath))
-		}
-
-		// home path
-		homePath, err := os.UserHomeDir()
-		if err == nil {
-			paths = append(paths, homePath, homePath+"/"+app, homePath+"/.config", homePath+"/.config/"+app)
-		}
-		paths = append(paths, "/etc", "/etc/"+app, "/usr/local/etc", "/usr/local/etc/"+app)
-
-		log.Println("try load config from paths:", paths)
-		for _, path := range paths {
-			v.AddConfigPath(path)
-		}
+		v.SetConfigFile(file)
 	} else {
+		v.SetConfigType(ext[1:])
 		v.SetConfigFile(file)
 	}
 
+	v.AddConfigPath(".")
+
 	err := v.ReadInConfig()
-	log.Println("use config file:", v.ConfigFileUsed())
+	log.Println("config file:", v.ConfigFileUsed())
 	if err != nil {
 		return nil, errors.Wrap(err, "config file read error")
 	}